Abstract: Methods and apparatus for detecting a magnitude of a voltage at a face of a conducted electrical weapon (“CEW”). The magnitude of the voltage may be used to determine whether a pulse of a stimulus signal was delivered to a target. Structures for detecting the magnitude of the voltage may include structures that provide a stimulus voltage.

Abstract: A toy dart includes a deformable cap that safely impacts a target. The cap includes two layers of substantially parallel hollow passages that provide spaces that allow the cap to deform. The lower layer, having two hollow passages, is supported by exterior posts and an interior wall between the two hollow passages. The upper layer, having three hollow passages, is supported by exterior posts and interior walls that are laterally offset from the interior wall of the lower layer. The upper and lower layers are separated vertically by a substantially flat divider. Due to the difference in the number of hollow passages and interior walls in each layer, the upper layer is more rigid than the lower layer such that the lower layer of the cap deforms more than the upper layer of the cap upon initial impact with the target.

Abstract: An elongate cylindrical projectile including processing circuitry, a head assembly, a tail section assembly, a mid body section positioned between the head assembly and tail assembly, and a wing assembly, the wing assembly including a deployable wing which is stored in a closed position entirely within the mid body section and is deployed, using an actuator, to outside the mid body section in an open position in response to a command from the processing circuitry.

Abstract: A device is configured for deflecting a stream of particles for a projectile guided by a link wire, the projectile having a fuselage and an engine capable of producing a propulsive jet containing the stream of particles. The device includes a device support including an inner surface configured to attach the device support to the fuselage of the projectile, and a deflector strip assuming at least an unfolded position in which the deflector strip forms an angle with the device support in order to deflect the stream of particles.

Abstract: An internally coupleable joint is disclosed. The joint can include a first component and a second component configured to mate with one another in an end-to-end relationship. An axially extending protrusion of the first component can interface with a corresponding recess of the second component. In addition, the first component and the second component can each have an internal coupling feature extending at least partially about an inner circumference of the respective component. The joint can also include a securing member having external coupling features configured to engage the internal coupling features of the first and second components to prevent separation of the first and second components.

Abstract: A rolling preventer for reducing rolling movements of a grenade, wherein the rolling preventer has at least one hindering element, which counteracts rolling movements of the grenade and can consequently reduce the rolling movement. The rolling preventer according to the invention also has a clearance, by which the rolling preventer can be attached to a grenade. For this purpose, the grenade is inserted through the clearance and the rolling preventer is thereby fastened to the grenade. Also proposed is a grenade, with a housing, an actuating element and a safety device, wherein the grenade is equipped with a rolling preventer according to the invention.

Abstract: A housing arrangement comprising a housing wall with internal cavities which contribute to relieving the pressure in the interior and to increasing the deformation resistance of the housing. A housing of this kind can be designed to be large in volume yet light in weight.

Abstract: The present invention provides a diffuser cup or ring adapted to hold a primer used in an ammunition cartridge comprising a bottom surface sized to fit in a primer recess for an ammunition cartridge; a diffuser aperture positioned through the bottom surface and aligned with a flash hole; a cup wall attached to the bottom surface and extending away from the bottom surface; and an interior cavity bordered by the cup wall and the bottom surface and sized to frictionally fit a primer.

Abstract: The invention provides an apparatus and method for preventing surrounding loose rock fragments from falling or collapsing into a blast hole. The apparatus includes a flexible sheet including a pair of spaced apart longitudinally extending side edges and a pair of spaced apart laterally extending end edges. The sheet has a curved form defining a longitudinal passage extending between openings at longitudinally opposite ends, one end of the curved sheet being insertable into the open end of a blast hole whereby the curved sheet closely faces an internal surface of the blast hole and forms a barrier preventing surrounding loose rock fragments from falling or collapsing into the open end of the blast hole. The invention also provides a bench blasting method and a deployment device for deploying the apparatus into a blast hole.

Abstract: Provided is a compact-sized tape measure including a housing, a reel rotatably mounted in the housing, and a blade wound on an outer surface of the reel and drawn out through an inlet of the housing, in which the reel includes a spring providing a force for winding the blade and a bobbin providing an inner space receiving the spring and an outer space for winding and storing the blade, and a width of a spring receiving space capable of receiving the spring in the inner space is larger than a width of a blade receiving space capable of receiving the blade in the outer space.

Abstract: A carpentry device including a main arm having a width and length configured to measure distances of an object. The main arm can include indicia markings on a face of the main arm for measuring distances of an object. The main arm can be formed from one or more sections configured to extend or retract in a longitudinal direction, including at least one supplemental arm extending from at least one connection point at an end of the main arm such that the at least one supplemental arm can rotate about the at least one connection point. A digital angle finder can be attached to the at least one connection point to display an angle between the at least one connection point and the main arm. A bubble level can be attached to the face of the main arm.

Abstract: A measuring system comprising a measuring apparatus including a first portion comprising a first casing, a first length measuring body, a first length measuring device, and a first reference point. A first end of the first length measuring body is attached to the first casing, a second end extends away from the first casing, the first length measuring device measures a first distance between the second end and the first reference point; a second portion comprising a second casing, a second length measuring body, a second length measuring device, and a second reference point. A first end of the second length measuring body is attached to the second casing, a second end extends away from the second casing, the second length measuring device measures a second distance between the second end and the second reference point. The first and second portion are coupled and rotate relative to each other.

Abstract: A three-coordinate measuring system includes a three-coordinate measuring apparatus, and a type collector for a product to be measured; the apparatus is provided with a probe, and a control component which controls motion of the probe through a measuring program preset according to product type of the product to be measured, the control component is electrically connected to the probe; the type collector includes an optical collecting head capable of scanning a graphic identifier, the optical collecting head is electrically connected to the control component; the control component acquires the product type of the product to be measured according to the graphic identifier scanned by the optical collecting head, and call a corresponding measuring program to control the motion of the probe in order to measure the product to be measured and acquire measuring data, a method for three-coordinate measuring is also provided.

Abstract: A positioning apparatus including a quill on which a probe apparatus can be mounted, at least one motor for positioning the quill in a substantially vertical dimension, and a pneumatic counterbalance mechanism for the quill. The positioning apparatus is configured, based on at least one factor relating to the quill, to automatically effect a change in the pneumatic counterbalance mechanism's pressure so as to thereby adapt the counterbalance force on the quill provided by the pneumatic counterbalance mechanism.

Abstract: In some examples, a device can be used for measuring a length of a wear indicator on a brake assembly. The device includes a moveable component configured to move based on contact with the wear indicator. The device also includes a sensor configured to detect a displacement of the moveable component. The device further includes processing circuitry configured to determine the length of the wear indicator based on the displacement of the moveable component detected by the sensor.

Abstract: A wheel flange height difference detection and annular groove burr clearing device includes a turntable, a detection platform, a first intelligent compression meter, a second intelligent compression meter, a first burr cutter, a second burr cutter and the like.

Abstract: A localization and attitude estimation method using magnetic fields includes the following steps. First, in three-dimensional coordinates, at least three magnetic landmarks arbitrarily disposed around a moving carrier are selected, wherein any two of the at least three magnetic landmarks have different magnetic directions. One set of at least five tri-axes magnetic sensors is used to sense the magnetic fields of the at least three magnetic landmarks. Three magnetic components on three axes of a current position of each of the tri-axes magnetic sensors are respectively generated by a demagnetization method. Five non-linear magnetic equations are solved to obtain position information and magnetic moment information of the at least three magnetic landmarks in the three-dimensional coordinates. Position vectors and attitude vectors of the set of at least five tri-axes magnetic sensors in a three-dimensional space are estimated based on tri-axes magnetic moment vectors of the magnetic landmarks.

Abstract: A magnetic position sensor for determining the angular position of a magnet on a rotatable component, comprising: at least one magnetic sensor for determining different vector components of a magnetic field of the magnet; a memory having a look-up table stored therein that is populated with data representative of different angular positions of the magnet, the data representative of each angular position being correlated with data in the look-up table that is representative of the vector components that would be detected by the at least one magnetic sensor at that angular position; wherein the magnetic position sensor is configured to use the vector components determined by the magnetic sensor and logic to determine the angular position of the magnet from the look-up table.

Abstract: Interferometric systems and methods for measuring rotational movement are described. In one implementation, an interferometer for measuring rotational movement includes a housing and a light source within the housing configured to project coherent light toward a non-coded surface of an object. The interferometer further includes at least one optical element configured to modify the projected coherent light in a manner accounting for a rotation of the object. The interferometer also includes at least one sensor within the housing including at least one light detector configured to detect reflections of the modified projected coherent light from the opposing non-coded surface as the object rotates relative to the housing. The interferometer further includes at least one processor configured to receive input from the at least one sensor and determine an amount of rotation of the object around the at least one rotational axis.

Abstract: A wavelength tunable laser device includes a gain element positioned in an optical cavity that provides optical gain to an optical signal. A frequency shifter that generates a frequency shift as a function of time is positioned in the optical cavity. The optical cavity is configured so that a magnitude of the frequency shift as a function of time generated by the frequency shifter is substantially equal to a frequency separation of a cavity mode of the cavity such that an output of the cavity generates laser light having a wavelength that tunes as a function of time.

Abstract: The present subject matter at least provides an apparatus for characterization of a slab of a material. The apparatus comprises two or more frequency-domain optical-coherence tomography (FD-OCT) probes configured for irradiating the slab of material, and detecting radiation reflected from the slab of material or transmitted there-through. Further, a centralized actuation-mechanism is connected to the OCT probes for simultaneously actuating elements in each of the OCT probes to cause a synchronized detection of the radiation from the slab of material. A spectral-analysis module is provided for analyzing at least an interference pattern with respect to each of the OCT probes to thereby determine at least one of thickness and topography of the slab of the material. Further, in some embodiments, the slab of material may include a passivation layer. The apparatus may be configured to determine a thickness of the passivation layer.

Abstract: The present subject matter at least provides an apparatus for inspecting a slab of material including a passivation layer. The apparatus includes a frequency-domain optical-coherence tomography (OCT) probe configured to irradiate the slab of material, and detect radiation reflected from the slab of material. The apparatus also includes a spectral-analysis module configured to analyze at least an interference pattern with respect to the OCT probe to thereby determine a thickness of the slab of the material. The apparatus also includes a thin-film gauge configure to determine a thickness of the passivation layer such that the determined thickness of the slab of material may be adjusted baes on the thickness of the passivation layer.

Abstract: An image capturing apparatus includes: a coordinate value acquisition unit that acquires first coordinate values serving as position information of a moving target; an image capturing unit that captures an image of the target; a direction and distance calculation unit that calculates a direction of an optical axis that connects the target and the image capturing unit and a distance between the target and the image capturing unit on the optical axis on the basis of the first coordinate values and second coordinate values serving as position information of the image capturing unit; an attitude control unit that controls an attitude of the image capturing unit on the basis of the calculated direction of the optical axis; and an imaging magnification setting unit that sets an imaging magnification of the target in the image capturing unit on the basis of the calculated distance, wherein the image of the moving target is captured while changing the imaging magnification of the target and the attitude of the image

Abstract: A smart lawn sensor is provided. The smart lawn sensor provides a grass height sensor adapted to determine the elevation of adjacent grass. The smart lawn sensor provides control circuitry operatively associated with the grass height sensor. The control circuitry may be programmed to set thresholds for the determined grass height so that the control circuitry sends notifications to one or more remote computing devices if the set thresholds are met or exceeded.

Abstract: A method of dimensioning an object includes: projecting, from a plurality of laser emitters disposed on a dimensioning device and having a predefined spatial arrangement forming a plane, respective laser beams onto a surface of the object, the laser beams oriented parallel to each other; controlling an image sensor of the dimensioning device, simultaneously with the projecting, to capture image data representing the surface and projections of the laser beams on the surface; detecting projection pixel coordinates in the image data representing the projections of the laser beams on the surface; detecting edge pixel coordinates in the image data representing edges of the surface; and determining a dimension of the surface based on the projection pixel coordinates, the edge pixel coordinates, and the predefined spatial arrangement.

Abstract: A method for checking the completeness of a container provided with a plurality of objects by means of a 3D camera includes providing a three-dimensional image of the objects and a multi-ROI. The multi-ROI includes a plurality of ROIs which have a user-settable shape and are arranged within the multi-ROI in a user-settable number of rows, columns and raster type, including a learning mode and a temporally subsequent working mode.

Abstract: To enable short-time measurement of a displacement at a predetermined position of a measurement object even when the position or the posture of the measurement object is changed. During operation of a displacement measuring apparatus, the position and the posture of a measurement object are determined by using position correction information, and a measurement position is corrected. The corrected measurement position is irradiated with measurement light. The measurement light that is emitted to and is reflected back from the measurement position is received by a light receiver. The light receiver outputs a received-light quantity distribution for displacement measurement, and a displacement at the measurement position is measured on the basis of the received-light quantity distribution.

Abstract: To enable measuring a displacement at a predetermined position of a measurement object for a short time at a high accuracy. While a scanning mirror is moved in a first scanning range to cause measurement light to irradiate a measurement position, a first irradiation angle of the scanning mirror at the time the measurement light is emitted to the measurement position is obtained. While a scanning mirror is moved in a second scanning range that covers the first irradiation angle and that is narrower than the first scanning range, and a second irradiation angle at the time the measurement light is emitted to the measurement position is obtained. A light receiver outputs a received-light quantity distribution, and a displacement at the measurement position is measured on the basis of the second irradiation angle and the position in a second direction of the measurement position.

Abstract: To enable measurement of a displacement at a predetermined position in the case in which a measurement object remains stationary and also in the case in which the measurement object moves. Alight projector and a scanning part are controlled to cause measurement light to sequentially irradiate different positions of the measurement object in a case in which a scanning mode is selected. On the other hand, the light projector and the scanning part are controlled to cause the measurement light to irradiate the same positions of the measurement object in a case in which a line mode is selected. The displacement of the measurement object is measured on the basis of a received-light quantity distribution output from a light receiver.

Abstract: To enable scanning using measurement light with a small-sized displacement measuring apparatus. The displacement measuring apparatus includes a MEMS mirror for scanning using measurement light that is output from a light projection lens. The light projection lens has a focus position, at which the measurement light is condensed, at the MEMS mirror or in the vicinity of the MEMS mirror on an optical axis of the measurement light. The measurement light that is reflected at the MEMS mirror spreads in a strip-shaped manner as the measurement light comes close to a measurement region.

Abstract: A method for measuring the thickness of coatings on metal substrates comprises illuminating a sample comprising a substrate and a coating with light waves of varying wavelengths from a light source, receiving the light waves reflected by the sample at a light collector, diffracting the light waves into a plurality of component wavelengths with a grating, detecting the light intensities of the plurality of component wavelengths at a detector array, generating a reflectance spectral curve using the detected light intensities for each of the plurality of component wavelengths, calculating the thickness of the coating from the reflectance spectral curves of the component wavelengths.

Abstract: An actuator of a camera module includes a position detector configured to generate a feedback signal based on a detected position of a lens barrel; and a driver configured to drive the lens barrel based on a difference between an input signal indicating a target position of the lens barrel and the feedback signal, wherein the driver includes a signal adjuster configured to calculate an offset between the target position of the lens barrel and an actual position of the lens barrel, and apply the input signal to a calibration function based on the offset to generate a calibrated input signal.

Abstract: A method for sensing a parameter of an environment surrounding an optical fiber comprises performing a distributed analysis of one or more guided acoustic wave Brillouin scattering (GAWBS) processes taking place therein.

Abstract: The invention relates to an online measurement system and method for multiple parameters of a wheel based on structured light. The measurement system comprises a wheel sensor, a first wheel online measurement device and a second wheel online measurement device, and is characterized in that both the first wheel online measurement device and the second wheel online measurement device comprise a tread structured light unit, a profile structured light unit and a two-dimensional image sensor. The tread structured light unit and the profile structured light unit project a profile contour curve and a tread contour curve on the wheel, the two-dimensional image sensor takes images, three-dimensional reconstruction is performed on the images to obtain tread contour information and profile contour information, and the wheel diameter, the wheel flange height and the wheel flange thickness are acquired according to the obtained contour information.

Abstract: A displacement measuring apparatus acquires, based on a principle of triangulation and corresponding to an incident position of the reflected light in the light receiving section, a profile that is an aggregate of heights of reflection positions of the planar measurement light in the measurement object. The displacement measuring apparatus drives the light guiding optical system such that a plurality of reflection positions arranged in a line along a first direction on a surface of the measurement object are minutely displaced in a second direction different from the first direction by reflecting the planar measurement light on the surface of the measurement object. The displacement measuring apparatus acquires one profile by statistically processing a plurality of sub-profiles acquired by minutely displacing the light guiding optical system.

Abstract: A method of non-destructively inspecting an adhesively bonded assembly of first, second, and third materials includes generating guided waves in the adhesively bonded assembly and establishing a dispersion curve plot in a first reference frame on the basis of receiving the guided waves. The method further includes comparing the dispersion curve plot with a plurality of reference dispersion curves established in the first reference frame, each of the reference dispersion curves being obtained by generating guided waves in a reference adhesively bonded assembly. Finally, the method includes estimating at least one of the thicknesses of the materials in the adhesively bonded assembly under inspection.

Abstract: The method includes: a first profile generation step of generating a first profile of irregularities in a measurement range set on the substrate sheet (2), based on first measurement information acquired at a location upstream of the coating machine (30) and indicating a shape of irregularities of the substrate sheet (2); a second profile generation step of generating a second profile of irregularities in the measurement range, based on second measurement information acquired at a location downstream of the coating machine (30) and indicating the shape of the irregularities of the substrate sheet (2); and a coating amount calculation step of calculating the amount of the applied coating from a difference between the first measurement information and the second measurement information, based on a positional relationship in which the shape of the first profile of irregularities and the shape of the second profile of irregularities are matched to each other.

Abstract: Measurement approaches and data analysis methods are disclosed for combining 3D topographic data with spatially-registered gas concentration data to increase the efficiency of gas monitoring and leak detection tasks. Here, the metric for efficiency is defined as reducing the measurement time required to achieve the detection, or non-detection, of a gas leak with a desired confidence level. Methods are presented for localizing and quantifying detected gas leaks. Particular attention is paid to the combination of 3D spatial data with path-integrated gas concentration measurements acquired using remote gas sensing technologies, as this data can be used to determine the path-averaged gas concentration between the sensor and points in the measurement scene.

Abstract: An optoelectronic device has an asymmetric field overlap and is operable to measure proximity independently of object surface reflectivity. In some instances, the optoelectronic device includes a plurality of light-emitting assemblies and a light-sensitive assembly. In some instances, the optoelectronic devices include a plurality of light-sensitive assemblies and a light-emitting assembly. An asymmetric field overlap is attained in various implementations via various field-of-view axis, field-of-view angle, field-of-illumination axis, field-of-illumination angle, optical element and/or pitch configurations.

Abstract: The interior of a first measurement surface and the interior of a second measurement surface traveling together with a measuring vehicle are scanned to acquire first measurement coordinate points and second measurement coordinate points, respectively. A first comparison point cloud representing a comparison part on a surface of a structure is extracted from the first measurement coordinate points. A second comparison point cloud representing a comparison part on the surface of the structure is extracted from the second measurement coordinate points. A difference between the first comparison point cloud and the second comparison point cloud corresponding to measurement of a common comparison part on the surface of the structure is calculated. Error having time dependence included in the first measurement coordinate points and the second measurement coordinate points is calculated on the basis of the calculated difference. The measurement coordinate points are corrected on the basis of the calculated error.

Abstract: A leveling sensor, a load port including a leveling sensor, and a method of leveling a load port using a load port are disclosed. In an embodiment, a sensor includes an accelerometer configured to detect leveling and vibration of a load port and produce a plurality of data; a plurality of indicator lights configured to display a level measurement and a level direction based on the leveling of the load port; a processor configured to process the data produced by the accelerometer; and a wired connection configured to connect the processor to an external device.

Abstract: A method for detecting a displacement of a mobile platform is provided. The method includes acquiring a first frame and a second frame using an imaging device that is coupled to the mobile platform, and obtaining rotation data using an inertial measurement unit (IMU) that is coupled to the mobile platform. The method also includes calculating a translation array based on the first frame, the second frame, and the rotation data. The method further includes determining the displacement of the mobile platform based on the translation array.

Abstract: The present disclosure relates to a method and a device for monitoring the water volume change, and a computer device and a storage medium. The method includes: acquiring a lake shoreline change sequence, a lake area change sequence, and a combined altimetry water level sequence; obtaining a lake water level sequence based on the combined altimetry water level sequence and the lake shoreline change sequence; calculating a first regressive relationship between the lake water volume and the lake water level based on the lake area change sequence and the lake water level sequence; and obtaining a lake water volume change sequence based on the lake water level sequence and the first regressive relationship between the lake water volume and the lake water level.

Abstract: A gyro vibrating element includes a drive signal pattern including a drive signal electrode to which a drive signal is applied and a drive signal wire connected to the drive signal electrode, a first detection signal pattern including a first detection electrode that outputs a first detection signal and a first detection signal wire connected to the first detection electrode, the first detection signal pattern being capacitively coupled to the drive signal pattern, and a second detection signal pattern including a second detection electrode that outputs a second detection signal opposite in phase to the first detection signal and a second detection signal wire connected to the second detection electrode, the second detection signal pattern being capacitively coupled to the drive signal pattern. Any one of the first detection signal pattern, the second detection signal pattern, and the drive signal pattern includes an adjustment pattern for adjusting an area of the signal pattern.

Abstract: The invention concerns a resonator 1 configured to be integrated into an inertial angular sensor, said resonator 1 comprising at least one mass suspended by mechanical springs 5, a number N of pairs Pi (2?i?N) of electrostatic springs 50, said resonator 1 defining at least four axes of symmetry S1, S2, S3 and S4, characterized in that: each pair Pi consists of two electrostatic springs 50 each having a privileged axis of action, these electrostatic springs 50 being positioned so that their respective axes form a right angle; for at least one spring of one of the pairs and one spring of another pair, the angle formed by these two springs is equal to a predefined angle.

Abstract: Example navigation aids for increasing the accuracy of a navigation system are disclosed herein. An example method disclosed herein identifying, with an aircraft intent description language (AIDL) aid, an AIDL instruction as associated with a first dynamic activity level of a plurality of dynamic activity levels and determining, with the AIDL aid, an aircraft state to be affected by the AIDL instruction. The example method also includes changing, with a navigation filter, a weighting scheme for a measurement of the aircraft state obtained by an inertial navigation system (INS) of the aircraft and estimating, with the navigation filter, a trajectory of the aircraft based on the weighting scheme and the measurement.

Abstract: A robotic system is disclosed that uses autonomous tunnel navigation. The system includes a plurality of sensors (e.g., ranging, odometry) to measure a distance from the robotic system to a plurality of walls. Memory stores instructions and a processor is coupled to the memory and the plurality of sensors to execute the instructions. The instructions cause the robotic system to detect movement of the robotic system through a surrounding environment based on sensor measurements, determine if the robotic system is in a tunnel based on the sensor measurements, and navigate with the odometry-based sensor when the robotic system is determined to be in the tunnel or the ranging sensor when the robotic system is determined to be not in the tunnel.

Abstract: Embodiments of the present disclosure are directed to systems and methods for determining a vehicle orientation. In one implementation, a computer-implemented method for determining a vehicle orientation may include receiving a first set of satellite signals associated with a connected device positioned relatively stationary with respect to a vehicle. The method may also include determining that the first set of satellite signals is insufficient to determine the vehicle orientation. The method may further include determining the vehicle orientation based on a first relative orientation of the connected device relative to the vehicle and a second relative orientation of the connected device relative to a reference object.

Abstract: Systems and methods are provided for estimating a walking speed of a subject. A method comprises mounting an inertial measurement unit (IMU) on a wrist of the subject, the IMU configured to generate acceleration and rate of turn signals; processing the acceleration and rate of turn signals from the IMU to generate a pitch angle and a roll angle; processing the pitch angle and the roll angle to generate a rotation matrix from a sensor frame of the IMU to a navigation frame of the subject; applying the rotation matrix to the acceleration signals and removing gravitational acceleration to generate an external acceleration signal; processing the external acceleration signal to determine a principal horizontal axis and to generate a principal component acceleration signal representing external acceleration along the principal horizontal axis; and processing the principal component acceleration signal using a regression-based method to determine an estimated walking speed of the subject.

Abstract: A transfer guiding device includes: a reception unit that receives a destination of a first vehicle used by a user; a search unit that searches for first and second routes along which the user travels from the first vehicle's current location to the destination respectively by the first vehicle and by the first and second vehicles; a calculation unit that calculates a first arrival time at which the user arrives at the destination by the first route, based on a first required time to travel through the first route, and a second arrival time at which the user arrives at the destination by the second route, based on a second required time to travel through the second route; and a transmission unit that transmits a message for recommending the user to transfer to the second vehicle when the first arrival time is later than the second arrival time.